Expansible pulley.



PATENTED JUNE 19, 1906.

E. E. JAMES. EXPANSIBLE PULLEY. APruoATloir FILED 110v. 20. 1006.

UNITED STATES PATENT: oFFioE.

I Specification of Letters Patent.-

Patented June 19, 1906.

Application filed November 20,1905. Serial No. 288,271.

engineer, a subject of the King of Great Britain and Ireland, residing at Bendigonia,

St. Kilda Road, Melbourne, county of Bourke,

in the State of Victoria, Commonwealth of Australia, have invented certain new and useful Improvements in Expansible Pulleys, of

- which the following is a specification.

quirements and varying tensions on the driving belt or chain; but with my invention the .raisin or lowering of the gear is effected au quently much lengthened.

The object of my invention is to provide an improved pulley for transmitting power by means of a driving belt or chain, which pulley will notonly be capable of automatically expanding or contracting, but will also act as a cushion to regulate and diminish the strain uponthesaid belt or chain.

My inventionautomatically regulates the gear and will be of great utility when applied to engines driving motor-velocipedes and automobiles. It is well known that when an incline has to be ascended or when an engine is first started the strain upon the driving belt or chain is severe and often causes the breaka e of the said belt or chain. In addition, the llfO of the ordinary pulley attached to the engine-shaft is of short duration, owing to the severity of the strain. With my invention fitted to a motor-velocipede or automobile it is possible to ascend an incline with'greater ease, with less power, and also with considerably less strain or tension upon the belt or wearing parts. In operation the strain of the belt or chain is taken up by my expansible pulley, which, as it expands in the manner hereinafter described, automatically lowers the gear, and thus renders the ascent of greater ease and at a reduced cost of power.

In the past various devices have been used to raise or lower a gear to suit various retomatlcally and the strain gradually absorbed bysprings. The wear uipon the pulley is more evenly distributed, an its lifeconse- My invention consists of few parts, all of which are of easy accessibility for adjustment or repair. The parts are cheap in first cost, and my invention may, in a few moments, be fitted to an ordinary engineshaft.

In the accompanying drawings, illustrating my invention}, I have shown it as particularly suitable for attachment to a belt-driven motor velocipede or automobile; but it will be clearly understood that with but slight modification it is applicable to various descriptions of shafts for transmitting power.

The slack in the belt or chain which ensues as the driving belt or chain descends into the V-shaped groove in the expansible pulley is taken up by a jockey or guide-roller and support of any suitable construction and mounted where convenient.

Referring to the drawings which form a part of this specification, Figure l is a longitudinal section of my expansible pulley. Fig. 2 is a side elevation, on a reduced scale, of the inner bevel-shaped disk dismembered and looked at in the direction of the arrow in Fig. 1. Fig. 3 is a similar view of the outer bevel shaped disk. Fig. 4 is a similar View of the adjusting-ring. Fig. 5 is a detailed view of the same ring looked at from the opposite side. Fig. 6 is a side elevation of Fig. 4, showing the adjustable springs in position. Fig. 7 is a view of the cover ona reduced scale looked at in the direction of the arrow in Fig. 1. Fig. Sis a detailed view of an adj listing-screw.

Similar letters of reference indicate similar or corresponding parts where they occur in the several views.

My invention includes an inner bevelshaped disk A, which has a boss A and an extension thereof A \Vithin the interior of the boss A is a slot A to accommodate a key or feather, which secures the pulley to the engine-shaft. In the boss A are three, four, or more threaded holes H to accommodate the threaded portion H of guide pins or fins H, hereinafter mentioned. Adjacent to the inner bevel-sha ed disk A is an outer bevel-shaped disk B, etween which is a V or wedge shaped groove C to accommodate the driving belt or chain. If necessary, the beveled faces of the inner disk A and the outer disk B are provided with ribs or projections to better rip the said driving belt or chain. Integrsfi with the outer bevelshaped disk B is a circular collar D and a shoulder B. This shoulder has integral therewith a flange B In the saidfiange B are made three, four, or more holes B to accommodate guide pins or fins H, upon which the outer bevel-sha ed disk slides or expands. Between the collar D and the shoulder B is a circular passage-way or recess J to accommodate adjustable springs J, hereinafter mentioned. The flange B embraces and IIO K therein turned also slides upon the extension A before mentioned.

Fitting into the collar D is a cover E. This cover has inwardly-projectin sides or lips E, around which the said collar slides. In the cover E are three, four, or more countersunk holes E to accommodate the uide pins or circular fins H. These fins H each ave a threaded extension H and a head which has a slot H by means of which it is screwed in position into the countersunk holes E The threaded extensions H engage in the holes H in the boss A. When more than the ordinary pressure or strain is put upon the driving belt or chain, the outer bevel-shaped disk B cushions the tension and slides along the fins H, thus spreading the strain and at the same time diminishing the gear.

To re ulate the movement of the outer bevel-dis B, I provide three, four, or more adjustable compression-springs J. The inner ends of these springs bear a ainst the outer disk B and are secured at t eir other ends within circular recesses G, formed in small bosses Gr upon the outer face of an adjusting-ring G. This adjusting-rm G fits Within the cover E. In the cover 4 are a series of three,\four, or more holes K to accommodate the heads K of adjustin -screws K The said screws have shoul ers K, which shoulders do not pass through the holes K in the cover E, but bear against the same.

When it is desired to regulate the distance the outer bevel-shaped disk B is to expand or slide, the heads K are by means of the slot either to the right or to the left, as is desired, or 'as the case may be. When the more than ordinary strain or pressure on the driving belt or chain is reduced, the outer bevel-shaped disk B is gradually forced by the adjustable s rings back into its normal position, an thus the gear is again raised.

It will be readily understood that my invention is ap licable to many descriptions of drivingul eys and is of such simple construction t at while it can in a few moments be regulated at will it is not likely to derangement. It will also save the time ordinarily spent in shortening a beltor chain that has stretched or lengthened, as in cases of chan es in'the Weather. In addition it will obviate delays caused by breakages.

Having now described my invention, what I claim as new, and desire to secure, by Letters Patent, is 4 In an expansible pulley, a beveled disk provided with a boss and an extension from the boss, an op ositely-beveled disk recessed to slide upon t e boss and provided with an annular collar, a cover fitted within said collar and secured to said boss, and a series of springs within said cover connected to a ring at one end and bearin at their op osite ends against the inner wal of one of t e beveled disks, substantially as described.

In testimony whereof I affix my signature in the presence of two subscribing witnesses.

EDWIN ERNEST JAMES.

Witnesses:

CECIL MoPLAsTRIER, GEo. A. URE 

